Joe Biden will be sworn in as president Wednesday, with significant changes to the ceremonies and celebrations due to two separate threats: COVID-19 and homegrown insurrectionists convinced that outgoing President Donald Trump should remain in power despite his election loss.

Biden will take his oath of office just two weeks after a deadly attack on the U.S. Capitol by Americans seeking to prevent the new administration from taking power. The violent mob that overwhelmed Capitol Police on Jan. 6 has transformed the inauguration from a traditionally high-security event to a national security crisis.

Presidential inaugurations receive a “national special security event” designation, which gives the Secret Service control over coordinating security. But the scale of military and security presence is unlike anything longtime Washingtonians and lawmakers have ever seen.

More than 20,000 National Guard troops are patrolling the nation’s capital city in the lead-up to inaugural ceremonies. Only about 8,000 National Guard members were on hand for Trump’s inauguration in 2017, when he invoked “American carnage.”

A massive multilayer perimeter that includes tall metal fencing, razor wire and checkpoints with armed National Guard members has been established around the Capitol.

Sen. Roy Blunt, chairman of the Joint Congressional Committee on Inaugural Ceremonies, said Tuesday that he’s feeling good about the security of the inauguration. He and the committee have been strategizing for months about how to safely hold the ceremonies amid a pandemic.

The Missouri Republican was one of the senators whisked out of the Senate chamber as violent mobs approached on Jan. 6. As Rules and Administration chairman, Blunt has oversight of the Capitol Police, the Senate sergeant-at-arms and the Office of the Attending Physician, all key planners for the inauguration.

“It’s clearly always a moment where our government is at its most vulnerable, but also an important moment where we project our strength as a democracy,” he said.

This is his second time at the helm of the JCCIC, and he maintains that the best moment for him is “when everybody got back inside.”

Instead of looking out at hundreds of thousands of people in front of him when he gives his inaugural address, Biden may primarily see the massive military presence and empty swath between the Capitol and the Washington Monument.

The National Mall, which was packed with approximately 1.8 million people for Barack Obama’s 2009 inauguration and thousands of people for Trump’s in 2017, will be completely closed to the public. Instead, close to 200,000 flags will be displayed on the Mall to represent people unable to attend the inauguration.

In addition to the domestic terrorism threat, Biden and Kamala Harris will take their oaths as the country surpasses 400,000 deaths from COVID-19.

In late December, the century-old tradition of the post-inauguration lunch was scrapped because of concerns about the ongoing pandemic.

“The health and safety of all guests attending the ceremonies has remained a top priority throughout the planning process,” Paige Waltz, the communications director for the JCCIC, said in a statement.

Statuary Hall in the Capitol will be quiet Wednesday, without the usual three-course meal and musical performance for the new Cabinet, the Supreme Court and congressional leadership. Instead, Biden, Harris and congressional leaders are expected to exchange gifts without a crowd and with masks on.

Members of the 117th Congress, who would usually get tickets to distribute to staff, donors, family and other guests, this year can bring only a single guest, in many cases a spouse or partner.

There will be no inaugural balls, a fixture of the Washington insider social circuit, on Wednesday. With large crowds, close proximity and indoor spaces posing acute danger of spreading COVID-19, the 2021 balls were quashed early in the planning process.

To replace the balls, there will be a TV special Wednesday night hosted by actor Tom Hanks, who recovered from COVID-19 back in the early days of the pandemic. The 90-minute program is called “Celebrating America” and will feature musical acts and remarks from both Biden and Harris.

The inaugural parade down Pennsylvania Avenue from the Capitol to the White House has also been eliminated amid coronavirus concerns. Instead, there will be a virtual parade entitled “Parade Across America,” which the Biden inaugural team says will feature “diverse, dynamic performances in communities across the country” and will pay “homage to America’s heroes on the front lines of the pandemic.”

Also moved to a digital event is the presidential inaugural prayer service on Thursday morning, hosted by the National Cathedral. Instead, Biden will join the virtual interfaith service put on by the National Cathedral, which will be livestreamed. Bishop William J. Barber II will deliver the homily, and the program will feature remarks from a wide array of religious voices and musical performances from Patti LaBelle, Josh Groban and The Clark Sisters.

After the swearing-in ceremony, Biden, Harris, incoming first lady Jill Biden and incoming second gentleman Doug Emhoff will participate in a “Pass in Review” on the East Front of the Capitol with members of the military.

“Pass in Reviews are a long-standing military tradition that reflect the peaceful transfer of power to a new Commander-in-Chief, during which the President-elect, hosted by the Commander of Joint Task Force-National Capital Region, will review the readiness of military troops. Every branch of the military will be represented in this event,” according to a statement from the Presidential Inaugural Committee. Participants will practice social distancing, and there will be “vigorous health and safety protocols in place,” according to the committee.

After the review of the troops, Biden and Harris, joined by Presidents Barack Obama, George W. Bush and Bill Clinton, will go to Arlington National Cemetery for a wreath-laying ceremony at the Tomb of the Unknown Soldier.

The ceremony will be one of Biden’s first official acts as the new commander in chief. The bipartisan trip to Arlington with former presidents is not an established inaugural tradition. Former first ladies Michelle Obama, Laura Bush and Hillary Rodham Clinton also will attend the ceremony at Arlington. The company of presidents from both parties, without Trump, is aligned with the theme of the whole inaugural event, “America United.”

Trump will not attend the inauguration. The move is not unprecedented but is extremely rare in the modern era. John Adams, John Quincy Adams and Andrew Johnson all skipped the swearing-in of their successors. And Richard Nixon departed the White House promptly after his resignation, not staying to attend Gerald Ford’s swearing-in.

Trump will not welcome the Bidens to the White House in the morning, and there won’t be the iconic images of the outgoing president flying away from the Capitol in a Marine Corps helicopter, with the new president and vice president waving farewell.

President Jimmy Carter, who is 96, and his wife, Rosalynn, 93, have said they will not travel for the event. This will be the first inauguration Carter has missed since attending his own in 1977.

Trump’s exit from Washington also comes as the Senate is set to embark on the unprecedented task of conducting an impeachment trial for a president who has left office. Trump, who was impeached by the House in December 2019 and acquitted in a Senate trial in February 2020, was impeached by the House again last week.

The new trial’s timing depends on when Speaker Nancy Pelosi transmits the House’s impeachment materials to the Senate.

Chris Cioffi contributed to this report.